Automatic safety brake



May 12, 1925.

F. L. MCCARTY ET AL AUTOMATI C SAFETY BRAKE FiIeid Sept. a; 1924 awn H 044 71.2%? (a 4 A7 761K422 arse.

' upon the Patented May 12, 1925.

UN Fran STATES PATENT OFF-ICE...

FRANK Ii. MGCARTY AN'D ALFREDR. ANDERSEN, OF ROCKv SPRINGS, W Y-OMING.

AUTOMATIC SAFETY BRAKE.

Application filed September 3,1924. SeriaLNo. 735,609;

Improvements in an Automatic Safety Brake, of which the following. is a specification.

Our invention relates broadly to vehicles, and more particularly to an emergency brake or check for mantrips, used in coal mines.

One of the objects of. our invention is to provide an automatic safety brake mechanism operative upon the breakingof a cable in atrip or train of cars for chucking the car wheels and bringing the car to a stop, thereby preventing a runaway with its inherent dangers;

Another object of our invention 1s to provide a simplified and practical construction of chuckfor a car wheel with means for suspendingv the chuck. from the vehicle body in such manner as tobecome .immediately operative between the car wheels and the rails for preventing. relative movement of thecars with respect to therails.

Still another object of our invention is to provide a safety device particularly adapted for said railway cars and mine'cars which are required to ascend or descend grades of large degrees comprising a chuck in the form of a. shoe adapted to enter between the tread of the car wheel. and. the rail at the same time that auxiliary mechanism is operated to sandthe rail for increasing the friction between the chuck and the rail surface;

Still another object of ourinvention is to provide a practical construction of emergenccy brake or check for mantrips embodying a small number of rugged partsnormally held in inoperative position by a cable extending through a seriesof cars and arranged to become immediately operative parting of the cable due to accidental separation of the cars whereby such cars are brought to a standstill.

Our invention will be more clearly understood from the following specification and by reference to the accompanying. drawings, in which:

Figure 1 is a. side elevation. ofone end of a car equipped with the automatic safety brake of my invention with a portion of the car broken away to show the interior mounting ofthe. brake mechanism; Fig. 2 is a view of a portion of the car showing the safety brake mechanism normally held out of engagement with the car wheel; Fig. 3 is a partial cross-sectional view taken on line 3'-8 of Fig. 1 and showing the arrangement ofthe safety brake mechanism with relation to the car wheel; Fig. 4 is a crosssectional view taken through the chuck or shoe which engages the car wheel; Fig. 5 is a-fragmentary View of the spring pressed valve, which controls the delivery of sand to the rail when the chuck becomes. engaged between the rail and wheel; andFigL6 is a diagrammatioview illustrating the arrangement of the automatic safety. brakes upon a plurality of mine cars ascending a steep grade. 7

Referring to the drawings in detail, reference character 1' indicates arail upon which the car is arranged to operate. Reference character 2 showsthe chuck or, shoe. ar-' ranged to slide beneath the car wheel upon the breaking of cable line 3 as will'be hereinafter described. The brake shoe2 is providedv with a lining 4 of belting or other material to provide a high frictional con tact with the surface of the rail v1. The shoe 2 has a pressed metal or cast block 5 thereon which engages with the tread surface of car wheel 6. The body of the car has been indicated generally at 7. While we have represented the automatic safety brake as applied toa mine car, it will be understood that it may be applied to street railway cars whereoccasion demands; The] wheel 6 is carried upon axle8 adjacent which the brake mechanism is mounted.

A shoe similar to that represented at 2 may bemounted on each side of the car-l I normally raised out of engagement with the tread of wheel 6 as indicated in Fig. 2. The

mechanism comprises a. shaft 9 extending laterally of the car with a vertical extension 10 in the formofv a T. centrally. posiin aportion 12 extending vertically or at.

right angles to the shaft 9. A journal 14: is provided on the extremity of portion 12 of shaft 9 in which is pivoted the end 15 of the shoe 2. A coil spring 16 is secured at a point 17 beneath the car body and attaches at a point 18 to the block 5 on shoe 2. The spring 16 normally tends to hold the brake shoe 2 off of the rail 1 and out of engagement with the tread of wheel 6 when the trip is in hoisting position. The shaft 9 is rotatably mounted in journalbox' 18 carried by car body 17 and-is normally held forward by cable 3-secured to the short lever 10 of shaft 9 against the action of compression spring 19 normally tending to force lever 10 in such position that the brake shoe 2 will engage the wheel 6. The pressure of spring 19 is resisted by the pull of cable 3 in such manner that should cable 3 snap and thereby release lever 10 the spring 19 will have its potential energy converted into kinetic energy and expended against lever 10, forcing brake shoe 2 in a downward direction against wheel 16.

lVe provide a sand box 20 mounted adjacent thebrake mechanism with a delivery tube 21 extending therefrom and a valve 2 f actuated by plunger 22 and spring 23 interposed in the said delivery pipe. The spring 23 is normallydepressed by reason of the abutting of the journal 14; against plunger 22 when the brake mechanism is in raised position. WVhen however the cable 3 snaps and the brake shoe 2 is forced down, the

' valve 24 opens and sand slides down de livery tube 21 and out through the delivery mouth 25 upon the rail 1.

In order to insure the aligning of the shoe 2 with the tread of the wheel 6 and the surface of rail 1, we provide a guide member 26 co-extensive with the shoe or chuck 2. This guide member 26 has a U shaped flange extending downwardly as indicated at 28 adjacent the flange of the rail 1 and upwardly as indicated at 29 in the direc tion of the flange 27 of the wheel 6. The distance between the sides 28 and 29 of the U shaped guide member 26 is substantially greater than the width of the car wheel flange 27 so that the shoe 2 becomes centered in position beneath the tread of the wheel 6 with the frictional surface 4 bearing upon rail 1. To further insure against the displacement of the brake shoe from the rail the lower surface of the brake shoe 2 is bent downwardly'at an angle as represented by reference character 31 so that the entire shoe may be rigidly capped over the rail.

The arrangement of the emergency brake as described herein upon mine cars has been successfully embodied by us in mine operation. Thls system of brake cars insures safety against runaways. In case of a coupling or a mean cable breaking our mechanism greatly reduces the danger of loss of life by a runaway car. Our mechanism finds particular application upon cars in a train of a plurality of cars. These cars often have tocarry six men each and ascend and descend at least a fifteen degree slope in 3.1111116: In case of a break serious injury might result to these men. In our system the cable 3 extends through the several cars and normally is placed under tension to hold brake shoe 2 away from the Wheel 6. Should this cable 3 part as represented by reference character 3 in the diagrammatic view in Fig.6 the shoe 2 is thrust under the wheel 6 which attempts to climb the inclined surface 5. 'At the same: s

time sand will have beenideposited on the surface of rail 1. The shoe 2 will have dropped in position upon rail 1 and become hooked against lateral displacement by means of the hook shaped member 26 as heretofore described. The frictional under surface 1- of the brake shoe 2 added tothe friction developed by the sand deposited simultaneously with the dropping of the shoe 2 insures the car against running away.

lVhile we have described'our invention in certain particular embodiments it will be understood that we intend no limitations upon the invention other than those imposed by the scope of the appended claims.

What we claim and desire. to secure by I Letters Patent of the United States is as follows:

1. An emergency brake for railway cars comprising in combination with a car body,

thrust said brake. shoe to a position intermediate said wheeland rail and means for normally rendering said last mentioned spring means inoperative. r

2. An emergency brake for railway cars comprising in combination with a car body, a rail, a wheel having a flange and a tread, a laterally extending shaft carried by said car body and mounted for limited rotative movement, a journal on one end of said shaft, a brake shoe pivotally mounted in said journal, said shoe having a frictional surface and an angularly disposed portion adapted to fit upon said rail, means for supplying sand to said rail, spring means for normally maintaining said brake shoe out of engagement with said wheel and rail and rendering said aforementioned meansto thrust said brake shoe to a position insaid shoe operating to prevent lateral distemnediate said Wheel and rail and means placement of said shoe with respect to said adapted to be longitudinally severed for rail. 10 releasing said last mentioned spring means 111 t stimony whe eOf e MEX 0H1 Signa- 5 for positioning said shoe upon said rail thressimultaneously with the delivery of sand FRANK L. MGCARTY. V thereon, said angularly disposed portion of ALFRED R. ANDERSEN. 

